Black Onyx was supposed to start from the No. 1 post in the Run for the Roses Saturday.

The horse's trainer said he has a chip in his left ankle and they are waiting for more information from the surgeon, but the injury is not catastrophic.

Trainer Kelly Breen said while it was a lot of hard work to get to the Derby and the horse's injury is disappointing, it's a blessing in disguise they found it this early.

"We noticed a little swelling in the ankle this morning, previous to training," Breen said. "It brought major concern right away. He went out, he trained, he did gallop. He came back and was, say, a one out of five lameness."

X-rays were scheduled for after training hours, shortly before the 9 a.m. scratch time deadline. A scratch announced before 9 a.m. would have allowed also-eligible Fear the Kitten to draw into the field.

Track officials said the No. 1 starting gate will remain empty and the remaining 19 horses will run from the post positions they drew earlier this week.

A Justice Department civil rights investigation has concluded that the Ferguson Police Department and the city's municipal court engaged in a "pattern and practice" of discrimination against African Americans, according to a U.S. law enforcement official.